Reductive Difunctionalization of Aryl Alkenes with Sodium Metal and Reduction-Resistant Alkoxy-Substituted Electrophiles.

A general method for alkali-metal-promoted reductive difunctionalization of alkenes has been developed by means of reduction-resistant alkoxy-substituted electrophiles. A series of 1,2-diboration and 1,2-dicarbofunctionalization products can be synthesized by employing trimethoxyborane and strained cyclic ethers such as oxirane and oxetane. In addition, unsymmetrical carbo- or thioborations have been accomplished via sequential treatment with trimethoxyborane and carbon or sulfur electrophiles.